Coordination compounds and their use for the polymerization of olefins

ABSTRACT

The invention relates to coordination compounds of the general formulae (1a) to (1b), wherein M=Ti, Zr, Hf, V, Nb or Ta. The invention also relates to a method for producing the metal complexes and to the use of the complexes so obtained for the polymerization and copolymerization of olefins. For example in suspension polymerization methods, gas phase polymerization methods and bulk polymerization methods.

[0001] The present invention relates to complexes of the formulae I aand I b,

[0002] where the variables are defined as follows:

[0003] M is selected from among Ti, Zr, Hf, V, Nb and Ta;

[0004] y corresponds to the oxidation state of M minus 1;

[0005] z corresponds to the oxidation state of M minus 2;

[0006] Nu is selected from among O, S and N—R⁵;

[0007] X are identical or different and are selected from among

[0008] halogen, C₁-C₈-alkyl, C₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl andC₆-C₁₄-aryl,

[0009] R¹ to R⁵ are identical or different and are selected from among

[0010] hydrogen,

[0011] C₁-C₁₈-alkyl, substituted or unsubstituted,

[0012] C₂-C₁₈-alkenyl, substituted or unsubstituted, having from one to4 isolated or conjugated double bonds;

[0013] C₃-C₁₂-cycloalkyl, substituted or unsubstituted,

[0014] C₇-C₁₃-aralkyl,

[0015] C₆-C₁₄-aryl, unsubstituted or substituted by one or moreidentical or different substituents selected from among

[0016] C₁-C₁₈-alkyl, substituted or unsubstituted,

[0017] C₂-C₁₈-alkenyl, substituted or unsubstituted,

[0018] C₃-C₁₂-cycloalkyl,

[0019] C₇-C₁₃-aralkyl,

[0020] C₆-C₁₄-aryl,

[0021] halogen,

[0022] C₁-C₆-alkoxy, substituted or unsubstituted,

[0023] C₆-C₁₄-aryloxy,

[0024] SiR⁶R⁷R⁸ and O—SiR⁶R⁷R⁸;

[0025] five- and six-membered nitrogen-containing heteroaryl radicals,unsubstituted or substituted by one or more identical or differentsubstituents selected from among

[0026] C₁-C₁₈-alkyl, substituted or unsubstituted,

[0027] C₂-C₁₈-alkenyl, substituted or unsubstituted,

[0028] C₃-C₁₂-cycloalkyl,

[0029] C₇-C₁₃-aralkyl,

[0030] C₆-C₁₄-aryl,

[0031] halogen,

[0032] C₁-C₆-alkoxy,

[0033] C₆-C₁₄-aryloxy,

[0034] SiR⁶R⁷R⁸ and O—SiR⁶R⁷R⁸;

[0035] where adjacent radicals R¹ to R⁵ may be joined to one another toform a 5- to 12-membered ring which may in turn bear substituentsselected from among C₁-C₈-alkyl, substituted or unsubstituted,C₂-C₈-alkenyl, substituted or unsubstituted and having from one to 4isolated or conjugated double bonds, C₃-C₁₂-cycloalkyl, substituted orunsubstituted, C₇-C₁₃-aralkyl and C₆-C₁₄-aryl;

[0036] R⁶ to R⁸ are identical or different and are selected from amonghydrogen, C₁-C₈-alkyl, C₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl andC₆-C₁₄-aryl.

[0037] The present invention also relates to a process for thepolymerization of olefins using complexes of the formulae I a and I b.

[0038] Polymers and copolymers of olefins are of great economicimportance because the monomers are readily available in largequantities and because the polymers can be varied within a wide range byvariation of the method of preparation or the processing parameters. Thecatalyst used is of particular significance in the process for preparingthe polymers. Apart from Ziegler-Natta catalysts, various single-sitecatalysts are of increasing importance. In the latter, central atomswhich have been examined in some detail include not only Zr as in, forexample, metallocene catalysts (H.-H. Brintzinger et al., Angew. Chem.1995, 107, 1255) but also Ni or Pd (WO 96/23010) or Fe and Co (e.g. WO98/27124). The complexes of Ni, Pd, Fe and Co are also referred to ascomplexes of late transition metals.

[0039] Metallocene catalysts have disadvantages for industrial use. Themost frequently employed metallocenes, namely zirconocenes andhafnocenes, are sensitive to hydrolysis. In addition, most metallocenesare sensitive to many catalyst poisons such as alcohols, ethers and Co,which makes it necessary for the monomers to be carefully purified.

[0040] While Ni and Pd complexes (WO 96/23010) catalyze the formation ofhighly branched polymers which are of little commercial interest, theuse of Fe or Co complexes leads to formation of highly linearpolyethylene containing very low proportions of comonomer.

[0041] EP-A 0 874 005 discloses further polymerization-active complexes.These complexes are preferably Ti complexes with salicylaldimineligands. These, too, bear phenyl substituents or substituted phenylsubstituents on the aldimine nitrogen (pages 18-23), or else thealdimine nitrogen is incorporated in a 6-membered ring (pages 31-32).However, they generally produce low molecular weight polyethylenes whichare not very suitable as materials. Furthermore, all the ligandsdisclosed in EP-A 0 874 005 have the oxygen atom as part of a phenolicsystem, which restricts the choice of readily available startingmaterials.

[0042] As G. J. P. Britovsek et al. show in Angew. Chem. 1999, 111, 448and Angew. Chem. Int. Ed. Engl. 1999, 38, 428, the search for veryversatile polymerization-active complexes continues to be of importancebecause of the great commercial importance of polyolefins. Particularattention has been attracted by complexes of the early transition metalswith bidentate ligands, for example complexes of the formula A,

[0043] which have been examined by X. Bei et al. in Organometallics1997, 16, 3282. However, the activities of the complexes in which M=Tior Zr in the polymerization of ethylene were too low for the complexesto be of commercial interest. T. Tsukahara et al. in Organometallics1997, 16, 3303 and I. Kim et al. in Organometallics 1997, 16, 3314 haveexamined β-hydroxypyridyl complexes of the formula B

[0044] and their activity in the polymerization of ethylene. If, forexample, R are each selected from among CH₃ and CF₃ and X is benzyl orneopentyl, only an extremely low polymerization activity, if any,opposite ethylene could be observed when the complex was activated withtrispentafluorophenylborane. On the other hand, ifR=para-tert-butylphenyl and X=benzyl, a low activity was observed, butthis was too low for commercial purposes. In addition, the polymersprepared in this way had a molecular weight M_(n) of 6200 g which is toolow for materials.

[0045] It is known from U.S. Pat. No. 3,997,471 that complexes formed insitu from β-hydroxynitriles and WCl₆ or their homologous molybdenumanalogues are able, after activation by various aluminum alkyl compoundssuch as ethylaluminum dichloride or diethylaluminum chloride, topolymerize cyclic olefins with opening of the ring.

[0046] It is therefore an object of the invention

[0047] to provide new complexes which are suitable for thepolymerization of olefins to give high molecular weight polyolefins;

[0048] to provide a process for preparing the complexes of the presentinvention;

[0049] to provide a process for the polymerization or copolymerizationof olefins using the complexes of the present invention;

[0050] to provide supported catalysts for the polymerization of olefinsand a process for preparing the supported catalysts of the presentinvention using the complexes of the present invention; and

[0051] to polymerize and copolymerize olefins using the supportedcatalysts of the present invention.

[0052] We have found that this object is achieved by means of complexeshaving the structures of the formulae I a and I b defined at the outset.

[0053] In formula I, the variables are defined as follows:

[0054] Nu is selected from among O, S and N—R⁵, with oxygen beingpreferred;

[0055] M is selected from among Ti, Zr, Hf, V, Nb and Ta in theoxidation states from +3 to +5; preferably Ti or Zr and particularlypreferably Zr;

[0056] y corresponds to the oxidation state of M minus 1,

[0057] z corresponds to the oxidation state of M minus 2, where M can bea metal in the highest oxidation state but does not have to be;

[0058] X are identical or different and are selected from among

[0059] halogen, such as fluorine, chlorine, bromine and iodine, withpreference being given to chlorine or bromine and particular preferencebeing given to chlorine;

[0060] C₁-C₈-alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl,neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl, sec-hexyl,n-heptyl, isoheptyl and n-octyl; preferably C₁-C₆-alkyl such as methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl,n-pentyl, isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl,n-hexyl, isohexyl, sec-hexyl, particularly preferably C₁-C₄-alkyl suchas methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl andtert-butyl;

[0061] C₃-C₁₂-cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl and cyclododecyl; preferably cyclopentyl, cyclohexyl andcycloheptyl;

[0062] C₇-C₁₃-aralkyl, preferably C₇-C₁₂-phenylalkyl such as benzyl,1-phenethyl, 2-phenethyl, 1-phenylpropyl, 2-phenylpropyl,3-phenylpropyl, neophyl (1-methyl-1-phenylethyl), 1-phenylbutyl,2-phenylbutyl, 3-phenylbutyl and 4-phenylbutyl, particularly preferablybenzyl; and

[0063] C₆-C₁₄-aryl, for example phenyl, 1-naphthyl, 2-naphthyl,1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl,3-phenanthryl, 4-phenanthryl and 9-phenanthryl, preferably phenyl,1-naphthyl and 2-naphthyl, particularly preferably phenyl.

[0064] X is preferably halogen.

[0065] R¹ to R⁵ are identical or different and are selected from among

[0066] hydrogen,

[0067] C₁-C₁₈-alkyl groups such as methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl,sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl,sec-hexyl, n-heptyl, isoheptyl n-octyl, n-decyl, n-dodecyl andn-octadecyl; preferably C₁-C₁₂-alkyl such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl,isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl,isohexyl, sec-hexyl and n-decyl, particularly preferably C₁-C₄-alkylsuch as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyland tert-butyl;

[0068] examples of substituted C₁-C₁₈-alkyl groups are: β-cyanoethyl,monohalogenated or polyhalogenated C₁-C₈-alkyl groups such asfluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl,dichloromethyl, trichloromethyl, bromomethyl, dibromomethyl,tribromomethyl, pentafluoroethyl, perfluoropropyl and perfluorobutyl,particularly preferably fluoromethyl, difluoromethyl, trifluoromethyland perfluorobutyl;

[0069] C₂-C₁₈-alkenyl having from one to 4 isolated or conjugated doublebonds, for example vinyl, 1-allyl, 3-allyl, o-butenyl, ω-pentenyl,ω-hexenyl, 1-cis-buta-1,3-dienyl and 1-cis-hexa-1,5-dienyl;

[0070] examples of substituted C₂-C₈-alkenyl groups are: isopropenyl,1-isoprenyl, α-styryl, β-styryl, 1-cis-1,2-phenylethenyl and1-trans-1,2-phenylethenyl;

[0071] C₃-C₁₂-cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl and cyclododecyl; preferably cyclopentyl, cyclohexyl andcycloheptyl;

[0072] examples of substituted cycloalkyl groups are:2-methylcyclopentyl, 3-methylcyclopentyl, cis-2,4-dimethylcyclopentyl,trans-2,4-dimethylcyclopentyl, cis-2,5-dimethylcyclopentyl,trans-2,5-dimethylcyclopentyl, 2,2,5,5-tetramethylcyclopentyl,2-methylcyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl,cis-2,6-dimethylcyclohexyl, trans-2,6-dimethylcyclohexyl,cis-2,6-diisopropylcyclohexyl, trans-2,6-diisopropylcyclohexyl,2,2,6,6-tetramethylcyclohexyl, 2-methoxycyclopentyl,2-methoxycyclohexyl, 3-methoxycyclopentyl, 3-methoxycyclohexyl,2-chlorocyclopentyl, 3-chlorocyclopentyl, 2,4-dichlorocyclopentyl,2,2,4,4-tetrachlorocyclopentyl, 2-chlorocyclohexyl, 3-chlorocyclohexyl,4-chlorocyclohexyl, 2,5-dichlorocyclohexyl,2,2,6,6-tetrachlorocyclohexyl, 2-thiomethylcyclopentyl,2-thiomethylcyclohexyl, 3-thiomethylcyclopentyl, 3-thiomethylcyclohexyland further derivatives;

[0073] C₇-C₁₃-aralkyl, preferably C₇-C₁₂-phenylalkyl such as benzyl,1-phenethyl, 2-phenethyl, 1-phenylpropyl, 2-phenylpropyl,3-phenylpropyl, neophyl (1-methyl-1-phenylethyl), 1-phenylbutyl,2-phenylbutyl, 3-phenylbutyl and 4-phenylbutyl, particularly preferablybenzyl;

[0074] C₆-C₁₄-aryl, for example phenyl, 1-naphthyl, 2-naphthyl,1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl,3-phenanthryl, 4-phenanthryl and 9-phenanthryl, preferably phenyl,1-naphthyl and 2-naphthyl, particularly preferably phenyl;

[0075] C₆-C₁₄-aryl such as phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl,2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl,4-phenanthryl and 9-phenanthryl substituted by one or more identical ordifferent substituents selected from among

[0076] C₁-C_(O) ₈-alkyl groups such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl,isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl,isohexyl, sec-hexyl, n-heptyl, isoheptyl n-octyl, n-decyl, n-dodecyl andn-octadecyl, preferably C₁-C₁₂-alkyl such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl,isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl,isohexyl, sec-hexyl and n-decyl, particularly preferably C₁-C₄-alkylsuch as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyland tert-butyl;

[0077] examples of substituted C₁-C₁₈-alkyl groups are: monohalogenatedor polyhalogenated C₁-C₁₈-alkyl groups such as fluoromethyl,difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl,trichloromethyl, bromomethyl, dibromomethyl, tribromomethyl,pentafluoroethyl, perfluoropropyl and perfluorobutyl, particularlypreferably fluoromethyl, difluoromethyl, trifluoromethyl andperfluorobutyl;

[0078] C₂-C₁₈-alkenyl having from one to 4 isolated or conjugated doublebonds, for example vinyl, 1-allyl, 3-allyl, ω-butenyl, ω-pentenyl,ω-hexenyl, 1-cis-buta-1,3-dienyl and 1-cis-hexa-1,5-dienyl;

[0079] examples of substituted C₂-C₈-alkenyl groups are: isopropenyl,1-isoprenyl, α-styryl, β-styryl, 1-cis-1,2-phenylethenyl and1-trans-1,2-phenylethenyl;

[0080] C₃-C₁₂-cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl and cyclododecyl; preferably cyclopentyl, cyclohexyl andcycloheptyl;

[0081] C₇-C₁₃-aralkyl, preferably C₇-C₁₂-phenylalkyl such as benzyl,1-phenethyl, 2-phenethyl, 1-phenylpropyl, 2-phenylpropyl,3-phenylpropyl, neophyl (1-methyl-1-phenylethyl), 1-phenylbutyl,2-phenylbutyl, 3-phenylbutyl and 4-phenylbutyl, particularly preferablybenzyl;

[0082] C₆-C₁₄-aryl, for example phenyl, 1-naphthyl, 2-naphthyl,1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl,3-phenanthryl, 4-phenanthryl and 9-phenanthryl, preferably phenyl,1-naphthyl and 2-naphthyl, particularly preferably phenyl;

[0083] halogen, for example fluorine, chlorine, bromine and iodine,particularly preferably fluorine and chlorine;

[0084] C₁-C₆-alkoxy groups such as methoxy, ethoxy, n-propoxy,isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy,isopentoxy, n-hexoxy and isohexoxy, particularly preferably methoxy,ethoxy, n-propoxy and n-butoxy;

[0085] C₆-C₁₄-aryloxy groups such as phenoxy, ortho-cresyloxy,meta-cresyloxy, para-cresyloxy, α-naphthoxy, β-naphthoxy and9-anthryloxy;

[0086] silyl groups SiR⁶R⁷R⁸, where R⁶ to R⁸ are selected independentlyfrom among hydrogen, C₁-C₈-alkyl groups, benzyl radicals and C₆-C₁₄-arylgroups; with preference being given to the trimethylsilyl,triethylsilyl, triisopropylsilyl, diethylisopropylsilyl,dimethylhexylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl,tribenzylsilyl, triphenylsilyl and tri-para-xylylsilyl groups andparticular preference being given to the trimethylsilyl group and thetert-butyldimethylsilyl group;

[0087] silyloxy groups OSiR⁶R⁷R⁸, where R⁶ to R⁸ are selectedindependently from among hydrogen, C₁-C₈-alkyl groups, benzyl radicalsand C₆-C₁₄-aryl groups; with preference being given to thetrimethylsilyloxy, triethylsilyloxy, triisopropylsilyloxy,diethylisopropylsilyloxy, dimethylhexylsilyloxy,tert-butyldimethylsilyloxy, tert-butyldiphenylsilyloxy,tribenzylsilyloxy, triphenylsilyloxy and tri-para-xylylsilyloxy groupsand particular preference being given to the trimethylsilyloxy group andthe tert-butyldimethylsilyloxy group;

[0088] five and six-membered nitrogen-containing heteroaryl radicalssuch as N-pyrrolyl, pyrrol-2-yl, pyrrol-3-yl, N-imidazolyl,2-imidazolyl, 4-imidazolyl, 1,2,4-triazol-3-yl, 1,2,4-triazol-4-yl,2-pyridyl, 3-pyridyl, 4-pyridyl, 3-pyridazinyl, 4-pyridazinyl,2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, N-indolyl and N-carbazolyl;

[0089] five- and six-membered nitrogen-containing heteroaryl radicalssuch as N-pyrrolyl, pyrrol-2-yl, pyrrol-3-yl, N-imidazolyl,2-imidazolyl, 4-imidazolyl, 1,2,4-triazol-3-yl, 1,2,4-triazol-4-yl,2-pyridyl, 3-pyridyl, 4-pyridyl, 3-pyridazinyl, 4-pyridazinyl,2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, N-indolyl and N-carbazolylsubstituted by one or more identical or different substituents selectedfrom among

[0090] C₁-C₁₈-alkyl groups such as methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl,sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl,sec-hexyl, n-heptyl, isoheptyl n-octyl, n-decyl, n-dodecyl andn-octadecyl, preferably C₁-C₁₂-alkyl such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl,isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl,isohexyl, sec-hexyl and n-decyl, particularly preferably C₁-C₄-alkylsuch as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyland tert-butyl;

[0091] examples of substituted C₁-C₁₈-alkyl groups are: monohalogenatedor polyhalogenated C₁-C₈-alkyl groups such as fluoromethyl,difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl,trichloromethyl, bromomethyl, dibromomethyl, tribromomethyl,pentafluoroethyl, perfluoropropyl and perfluorobutyl, particularlypreferably fluoromethyl, difluoromethyl, trifluoromethyl andperfluorobutyl;

[0092] C₂-C₁₈-alkenyl having from one to 4 isolated or conjugated doublebonds, for example vinyl, 1-allyl, 3-allyl, ω-butenyl, ω-pentenyl,ω-hexenyl, 1-cis-buta-1,3-dienyl and 1-cis-hexa-1,5-dienyl;

[0093] examples of substituted C₂-C₈-alkenyl groups are: isopropenyl,1-isoprenyl, α-styryl, β-styryl, 1-cis-1,2-phenylethenyl and1-trans-1,2-phenylethenyl;

[0094] C₃-C₁₂-cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl and cyclododecyl; preferably cyclopentyl, cyclohexyl andcycloheptyl;

[0095] C₇-C₁₃-aralkyl, preferably C₇-C₁₂-phenylalkyl such as benzyl,1-phenethyl, 2-phenethyl, 1-phenylpropyl, 2-phenylpropyl,3-phenylpropyl, neophyl (1-methyl-1-phenylethyl), 1-phenylbutyl,2-phenylbutyl, 3-phenylbutyl and 4-phenylbutyl, particularly preferablybenzyl;

[0096] C₆-C₁₄-aryl, for example phenyl, 1-naphthyl, 2-naphthyl,1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl,3-phenanthryl, 4-phenanthryl and 9-phenanthryl, preferably phenyl,1-naphthyl and 2-naphthyl, particularly preferably phenyl;

[0097] halogen, for example fluorine, chlorine, bromine and iodine,particularly preferably fluorine and chlorine;

[0098] C₁-C₆-alkoxy groups such as methoxy, ethoxy, n-propoxy,isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy,isopentoxy, n-hexoxy and isohexoxy, particularly preferably methoxy,ethoxy, n-propoxy and n-butoxy;

[0099] C₆-C₁₄-aryloxy groups such as phenoxy, ortho-cresyloxy,meta-cresyloxy, para-cresyloxy, α-naphthoxy, β-naphthoxy and9-anthryloxy;

[0100] silyl groups SiR⁶R⁷R⁸, where R⁶ to R⁸ are selected independentlyfrom among hydrogen, C₁-C₈-alkyl groups, benzyl radicals and C₆-C₁₄-arylgroups; with preference being given to the trimethylsilyl,triethylsilyl, triisopropylsilyl, diethylisopropylsilyl,dimethylhexylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl,tribenzylsilyl, triphenylsilyl and tri-para-xylylsilyl groups andparticular preference being given to the trimethylsilyl group and thetert-butyldimethylsilyl group;

[0101] silyloxy groups OSiR⁶R⁷R⁸, where R⁶ to R⁸ are selectedindependently from among hydrogen, C₁-C₈-alkyl groups, benzyl radicalsand C₆-C₁₄-aryl groups; with preference being given to thetrimethylsilyloxy, triethylsilyloxy, triisopropylsilyloxy,diethylisopropylsilyloxy, dimethylthexylsilyloxy,tert-butyldimethylsilyloxy, tert-butyldiphenylsilyloxy,tribenzylsilyloxy, triphenylsilyloxy and tri-para-xylylsilyloxy groupsand particular preference being given to the trimethylsilyloxy group andthe tert-butyldimethylsilyloxy group.

[0102] In a particularly preferred embodiment, at least one of theradicals R¹ to R⁴ is different from hydrogen. In a particularlypreferred embodiment, R² or R³ is different from hydrogen.

[0103] In a particular embodiment, adjacent radicals R¹ to R⁵ of thecomplexes of the formulae I a and I b may be joined to one another toform a 5- to 12-membered ring. For example, R¹ and R² may together be:—(CH₂)₃— (trimethylene), —(CH₂)₄— (tetramethylene), —(CH₂)₅—(pentamethylene), —(CH₂)₆— (hexamethylene), —CH₂—CH═CH—,—CH₂—CH═CH—CH₂—, —CH═CH—CH═CH—, —O—CH₂—O—, —O—CHMe-O—, —O—CH—(C₆H₅)—O—,—O—CH₂—CH₂—O—, —O—CMe₂—O—, —NMe-CH₂—CH₂—NMe-, —NMe-CH₂—NMe- or—O—SiMe₂—O— where Me=CH₃.

[0104] The complexes required for the process of the present inventionare obtainable from commercially available reagents in only a few steps.

[0105] The synthesis of the novel complexes of the formula I generallystarts out from a ligand of the formula II,

[0106] where the variables are as defined above.

[0107] The ligands of the formula II are firstly deprotonated by meansof a base and subsequently reacted with metal compounds of the formulaMX_(y+1).

[0108] Bases which can be used are the metal alkyls customary inorganometallic chemistry, for example methyllithium, ethyllithium,n-butyllithium, sec-butyllithium, tert-butyllithium or hexyllithium,also Grignard compounds such as ethylmagnesium bromide, also lithiumamide, sodium amide, potassium amide, potassium hydride or lithiumdiisopropylamide (“LDA”). Solvents which have been found to be usefulare high-boiling solvents such as toluene, ortho-xylene, meta-xylene,para-xylene, ethylbenzene or mixtures of these, also acyclic or cyclicethers such as 1,2-dimethoxyethane, tetrahydrofuran or diethyl ether.

[0109] This deprotonation is generally complete after a few hours; it isappropriate to employ a reaction time of from 2 to 10 hours, preferablyfrom 3 to 5 hours. The temperature conditions are generally notcritical; temperatures of from −90° C. to −20° C. are preferred for thedeprotonation.

[0110] The deprotonated ligand and the metal compound of the formulaMX_(y+1) are subsequently reacted with one another.

[0111] MX_(y+1) can optionally be stabilized by additional unchargedligands. Possible uncharged ligands are the customary ligands ofcoordination chemistry, for example cyclic and acyclic ethers, amines,diamines, nitriles, isonitriles or phosphines. Particular preference isgiven to diethyl ether, tetrahydrofuran, 1,2-dimethoxyethane,tetramethylethylenediamine, acetonitrile or triphenylphosphane.

[0112] The conditions for the reaction are not critical per se; it isusual to mix the deprotonated ligand II and MX_(y+1) with one another ina suitable solvent such as benzene, toluene, ethylbenzene, ortho-xylene,meta-xylene or para-xylene, chlorobenzene, cyclohexane, methylenechloride or a mixture of these. The temperature can be in the range from−100° C. to +150° C., preferably from −78° C. to +100° C. The reactiontemperature should not be less than the melting point of the solvent;temperatures above the boiling point of the solvent concerned can beachieved in an autoclave. It is important that the reaction is carriedout in the absence of oxygen and moisture.

[0113] The molar ratio of ligand to M can be in the range from 5:1 to1:5. However, since the ligands of the formula II are more difficult toobtain than the metal compounds, molar ratios of ligand:M in the rangefrom 1:1 to 1:3 are preferred. Particular preference is given tostoichiometric amounts.

[0114] However, if compounds of the formula I b are to be obtained,molar ratios of ligand:M of from 2:1 to 4:1 are preferred.

[0115] The novel complexes of the formulae I a and I b can be purifiedby the methods customary in organometallic chemistry, with particularpreference being given to crystallization and precipitation. Filtrationvia filter aids such as Celite® is also useful.

[0116] The preparation of the ligands of the formula II is described,for example, in U.S. Pat. No. 3,997,471. The preparation isadvantageously carried out by deprotonation of a nitrile of the formulaIII,

[0117] which bears an acidic α-H atom and subsequent reaction with anelectrophilic compound of the formula IV,

[0118] where the variables in the compounds III and IV are as definedabove.

[0119] Bases which can be used are the metal alkyls customary inorganometallic chemistry, for example methyllithium, ethyllithium,n-butyllithium, sec-butyllithium, tert-butyllithium or hexyllithium,also Grignard compounds such as ethylmagnesium bromide, also lithiumamide, sodium amide, potassium amide, potassium hydride or lithiumdiisopropylamide (“LDA”). Solvents which have been found to be usefulare, for example, toluene, ortho-xylene, meta-xylene, para-xylene,ethylbenzene or mixtures of these, also acyclic or cyclic ethers such as1,2-dimethoxyethane, tetrahydrofuran or diethyl ether.

[0120] This deprotonation is generally complete after from some minutesto a few hours; it is appropriate to employ a reaction time of from 30minutes to 10 hours, preferably from 1 to 5 hours. The temperatureconditions are generally not critical; temperatures of from −90° C. to+30° C.

[0121] The deprotonated nitrile III and the electrophilic compound IVare subsequently reacted with one another.

[0122] The conditions for the reaction are not critical per se; it isusual to mix the deprotonated nitrile III and the electrophilic compoundIV with one another in a suitable solvent such as benzene, toluene,ethylbenzene, ortho-xylene, meta-xylene or para-xylene, chlorobenzene,cyclohexane, methylene chloride or a mixture of these. The temperaturecan be in the range from −100° C. to +150° C., preferably from −78° C.to +100° C. The reaction temperature should not be less than the meltingpoint of the solvent; temperatures above the boiling point of thesolvent concerned can be achieved in an autoclave. It is important thatthe reaction is carried out in the absence of oxygen and moisture.

[0123] The molar ratio of III to IV can be in the range from 5:1 to 1:5.Preference is given to molar ratios of III:IV in the range from 3:1 to1:3 and particular preference is given to stoichiometric amounts.

[0124] It has been found that the novel complexes of the formulae I aand I b are suitable for polymerizing olefins. They are particularlyuseful for polymerizing and copolymerizing ethylene and propylene toform high molecular weight polymers. Complexes of the formula I b arechiral and can produce isotactic polypropylene in the polymerization ofpropylene.

[0125] For the novel complexes of the formulae I a and I b to becatalytically active, they have to be activated. Suitable activators areselected aluminum and boron compounds bearing electron-withdrawingradicals (e.g. trispentafluorophenylborane,trispentafluorophenylaluminum, N,N-dimethylaniliniumtetrakispentafluorophenylborate, tri-n-butylaimoniumtetrakispentafluorophenylborate, N,N-dimethylaniliniumtetrakis(3,5-bisperfluoromethyl)phenylborate, tri-n-butylarmoniumtetrakis(3,5-bisperfluoromethyl)phenylborate and trityliumtetrakispentafluorophenylborate). Preference is given todimethylanilinium tetrakispentafluorophenylborate, trityliumtetrakispentafluorophenylborate and trispentafluorophenylborane.

[0126] If boron or aluminum compounds are used as activators for thenovel complexes of the formulae I a and I b, they are generally used ina molar ratio of from 1:10 to 10:1, based on M. They are preferably usedin a ratio of from 1:2 to 5:1 and particularly preferably instoichiometric amounts.

[0127] Another suitable class of activators consists of aluminoxanes.The structure of the aluminoxanes is not known precisely. They areproducts which are obtained by careful partial hydrolysis of aluminumalkyls (cf. DE-A 30 07 725). These products are not in the form of purechemical compounds, but as mixtures of open-chain and cyclic structuresof the types V a and V b. These mixtures are presumably in dynamicequilibrium.

[0128] In the formulae V a and V b, the radicals Rm are each,independently of one another,

[0129] C₁-C₁₂-alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl,neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl, sec-hexyl,n-heptyl, isoheptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl, preferablyC₁-C₆-alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl,neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl, sec-hexyl,particularly preferably methyl;

[0130] C₂-C₁₂-cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl or cyclododecyl, preferably cyclopentyl, cyclohexyl orcycloheptyl;

[0131] C₇-C₂₀-aralkyl, preferably C₇-C₁₂-phenylalkyl such as benzyl,1-phenethyl, 2-phenethyl, 1-phenylpropyl, 2-phenylpropyl,3-phenylpropyl, 1-phenylbutyl, 2-phenylbutyl, 3-phenylbutyl or4-phenylbutyl, particularly preferably benzyl, or

[0132] C₆-C₁₄-aryl such as phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl,2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl,4-phenanthryl or 9-phenanthryl, preferably phenyl, 1-naphthyl or2-naphthyl, particularly preferably phenyl; and

[0133] n is an integer from 0 to 40, preferably from 1 to 25 andparticularly preferably from 2 to 22.

[0134] Cage-like structures for aluminoxanes are also discussed in theliterature (Y. Koide, S. G. Bott, A. R. Barron Organometallics 1996, 15,2213-26; A. R. Barron Macromol. Symp. 1995, 97, 15-25). Regardless ofthe actual structure of the aluminoxanes, they are suitable asactivators for the novel metal complexes of the formulae I a and I b.

[0135] Mixtures of various aluminoxanes are particularly preferredactivators in cases when the polymerization is carried out in a solutionin a paraffin, for example n-heptane or isododecane. A particularlypreferred mixture is the COMAO available commercially from Witco GmbH,which has the formula [(CH₃)_(0.9) (iso-C₄H₉)_(0.1)AlO]_(n).

[0136] To activate the complexes of the formulae I a and I b by means ofaluminoxanes, an excess of aluminoxane, based on M, is generallynecessary. Appropriate molar ratios of M:Al are in the range from 1:10to 1:10,000, preferably from 1:50 to 1:1000 and particularly preferablyfrom 1:100 to 1:500.

[0137] The chosen complex of the formula I a or I b and the activatortogether form a catalyst system.

[0138] The activity of the catalyst system of the invention can beincreased by addition of further aluminum alkyl of the formulaAl(R^(m))₃ or aluminoxanes; aluminum alkyls of the formula Al(R^(m))₃ oraluminoxanes can also act as molar mass regulators. A further effectivemolar mass regulator is hydrogen. The molar mass can be regulatedparticularly effectively via the reaction temperature and the pressure.If a boron compound as described above is to be used, the addition of analuminum alkyl of the formula Al(R^(m))₃ is particularly preferred.

[0139] Pressure and temperature conditions during the polymerization canbe chosen within wide limits. Pressures in a range from 0.5 bar to 4000bar have been found to be useful; preference is given to from 10 to 75bar or high-pressure conditions of from 500 to 2500 bar. A suitabletemperature range has been found to be from 0 to 120° C., preferablyfrom 40 to 100° C. and particularly preferably from 50 to 85° C.

[0140] As monomers, mention may be made of the following olefins:ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-deceneand 1-undecene, with propylene and ethylene being preferred and ethylenebeing particularly preferred.

[0141] Suitable comonomers are α-olefins, for example from 0.1 to 20 mol% of 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene,1-decene or 1-undecene. Further suitable comonomers are isobutene andstyrene, also internal olefins such as cyclopentene, cyclohexene,norbornene and norbornadiene.

[0142] Solvents which have been found to be suitable are toluene,ortho-xylene, meta-xylene, para-xylene and ethylbenzene and alsomixtures of these, also, under high-pressure conditions, supercriticalethylene.

[0143] The novel complex of the formula I a or I b can also be formed insitu in the polymerization reactor by mixing the deprotonated ligand IIand the transition metal compound MX_(y+1) in the polymerization reactorand, without isolating I a or I b, immediately activating the complex bymeans of one of the activators listed above. This method, too, alsomakes it possible to obtain the catalyst system of the presentinvention.

[0144] The catalyst systems of the present invention polymerize olefinsto give polyolefins having a very high molecular weight.

[0145] Hydrogen has been found to be an effective chain transfer agentin polymerizations using the catalyst systems of the invention, i.e. themolecular weight of the polymers obtainable by means of the catalystsystem of the present invention can be reduced by addition of hydrogen.If sufficient hydrogen is added, waxes are obtained. The hydrogenconcentration required for this depends, inter alia, on the type ofpolymerization plant employed.

[0146] For the catalyst systems of the present invention to be able tobe used in modern polymerization processes such as suspension processes,bulk polymerization processes or gas-phase processes, they have to beimmobilized on a solid support. Otherwise, morphology problems with thepolymer (lumps, deposits on walls, blockages in lines or heatexchangers) can occur and force shutdown of the plant. Such animmobilized complex will be referred to as a catalyst.

[0147] The catalyst systems of the present invention can be deposited onsolid support materials. Suitable support materials are, for example,porous metal oxides of metals of groups 2 to 14 or mixtures thereof,also sheet silicates and zeolites. Preferred examples of metal oxides ofgroups 2 to 14 are SiO₂, B₂O₃, Al₂O₃, MgO, CaO and ZnO. Preferred sheetsilicates are montmorillonites and bentonites; the preferred zeolite isMCM-41.

[0148] Particularly preferred support materials are spherical silicagels and aluminosilicate gels of the formula SiO₂.a Al₂O₃, where a isgenerally from 0 to 2, preferably from 0 to 0.5. Such silica gels arecommercially available, e.g. silica gel SG 332, Sylopol® 948 or 952 or S2101 from W. R. Grace or ES 70×from Crosfield.

[0149] As regards the particle size of the support material, meanparticle diameters which have been found to be useful are from 1 to 300μm, preferably from 20 to 80 μm, determined by known methods such assieve methods. The pore volume of these supports is from 1.0 to 3.0ml/g, preferably from 1.6 to 2.2 ml/g and particularly preferably from1.7 to 1.9 ml/g. The BET surface area is from 200 to 750 m²/g,preferably from 250 to 400 m²/g.

[0150] To remove impurities, in particular moisture, adhering to thesupport material, the support materials can be baked before doping, withtemperatures of from 45 to 1000° C. being suitable. Temperatures of from100 to 750° C. are particularly useful for silica gels and other metaloxides. This baking can be carried out for from 0.5 to 24 hours,preferably from 1 to 12 hours. The pressure conditions depend on theprocess chosen; baking can be carried out in a fixed-bed process, astirred vessel or else in a fluidized-bed process. Baking can in generalbe carried out at atmospheric pressure. However, reduced pressures offrom 0.1 to 500 mbar are advantageous, a range from 1 to 100 mbar isparticularly advantageous and a range from 2 to 20 mbar is veryparticularly advantageous. In the case of fluidized-bed processes, onthe other hand, it is advisable to employ a slightly superatmosphericpressure in a range from 1.01 bar to 5 bar, preferably from 1.1 to 1.5bar.

[0151] Chemical pretreatment of the support material with an alkylcompound such as an aluminum alkyl, a lithium alkyl or an aluminoxane islikewise possible.

[0152] It is also possible to form the novel complexes of the formula Ia or I b in situ and deposit them on the solid support material and thento deposit the activator on the support material. If such a method ofapplication to a support is chosen, the solid support material ispreferably freed of traces of moisture by baking before doping iscarried out.

[0153] In the case of a suspension polymerization process, use is madeof suspension media in which the desired polymer is insoluble or solubleto only a slight extent, because otherwise deposits of product occur inthe parts of the plant in which the product is separated off from thesuspension medium and force repeated shutdowns and cleaning operations.Suitable suspension media are saturated hydrocarbons such as propane,n-butane, isobutane, n-pentane, isopentane, n-hexane, isohexane andcyclohexane, with isobutane being preferred.

[0154] Pressure and temperature conditions during the polymerization canbe chosen within wide limits. A suitable pressure range has been foundto be from 0.5 bar to 150 bar, preferably from 10 to 75 bar. A suitabletemperature range has been found to be from 0 to 120° C., preferablyfrom 40 to 100° C.

[0155] As monomers, mention may be made of the following olefins:ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-deceneand 1-undecene.

[0156] Suitable comonomers are α-olefins, for example from 0.1 to 20 mol% of 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene,1-decene or 1-undecene. Further suitable comonomers are isobutene andstyrene, also internal olefins such as cyclopentene, cyclohexene,norbornene and norbornadiene.

[0157] Furthermore, hydrogen has been found to be an effective chaintransfer agent in polymerizations using the catalysts of the invention,i.e. the molecular weight of the polymers obtainable by means of thecatalysts of the present invention can be reduced by addition ofhydrogen. If sufficient hydrogen is added, waxes are obtained. Thehydrogen concentration required for this depends, inter alia, on thetype of polymerization plant employed. Addition of hydrogen increasesthe activity of the catalysts of the present invention.

[0158] The catalysts of the present invention can also be used togetherwith one or more other polymerization catalysts known per se. Thus, theycan be used together with

[0159] Ziegler-Natta catalysts,

[0160] supported metallocene catalysts containing transition metals ofgroups 4 to 6 of the Periodic Table of the Elements,

[0161] catalysts based on late transition metals (WO 96/23010),

[0162] Fe or Co complexes with pyridyldiimine ligands, as are disclosedin WO 98/27124 or

[0163] chromium oxide catalysts of the Phillips type.

[0164] If a plurality of catalysts is used, it is possible to mixvarious catalysts with one another and to meter them in together or touse cosupported complexes on a common support or else to meter variouscatalysts separately into the polymerization vessel at the same point orat various points.

[0165] The following examples illustrate the invention.

[0166] General Preliminary Remarks:

[0167] All work was, unless indicated otherwise, carried out withexclusion of air and moisture using standard Schlenk techniques.Apparatus and chemicals were prepared accordingly. The polymer viscositywas determined in accordance with ISO 1628-3.

[0168] 1. Preparation of the Ligands:

[0169] General Procedure Illustrated by way of Example by that forLigand II.3

[0170] 0.18 ml of diisopropylamine (1.3 nmol) was placed in a baked-outSchlenk tube which had been flushed with argon, dissolved in 10 ml ofTHF (absolute) and admixed at −80° C. with n-BuLi (0.72 ml, 1.1equivalents, 2.0 M solution in pentane). After removing the cold bath(EtOH, N₂), the resulting LDA solution was stirred at room temperaturefor {fraction (1/2)} hour.

[0171] Cyclohexylnitrile (0.144 g, 1.30 mmol) was added at −80° C. tothe freshly prepared LDA solution. After removing the cold bath, thedissolved starting material was stirred for 2 hours at room temperatureand thereby deprotonated (color change: yellowish to yellowish green).

[0172] 0.24 g of benzophenone (1.3 mmol) was subsequently added at roomtemperature and the mixture was stirred overnight.

[0173] The yellow THF solution was then poured into 100 ml of ice waterand extracted 3× with 25 ml each time of diethyl ether. The combinedorganic phases were washed with H₂O, dried over Na₂SO₄ and the organicsolvents were separated off on a rotary evaporator. The yellow productcrystallized out over a period of 2 hours. Subsequent recrystallizationfrom ethyl acetate/hexane gave the pure β-hydroxynitrile.

[0174] Ligand II.1

[0175] The synthesis of this ligand was carried out by the literaturemethod of E. Kaiser et al., J. Org. Chem. 1968, 33, 3403. The dataagreed with the literature data.

[0176] Ligand II.2

[0177] The synthesis of this ligand was carried out by the literaturemethod of T. Cuvigny et al., J. Organomet. Chem. 1973, 57, C36-C38.

[0178] Ligand II.3

[0179] Yield 59%, empirical formula: C₂₀H₂₁NO, m.p.: 179-180° C.

[0180] 1H NMR (CDCl₃): 1.11-1.17 (1H, m, CH₂), 1.61-1.79 (7H, m, CH₂),2.04-2.08 (2H, m, CH₂), 2.67 (1H, s, OH), 7.29-7.67 (10H, m, phenyl)

[0181] 13C NMR (CDCl₃): 22.8 (CH₂), 25.0 (CH₂), 30.8 (CH₂), 47.2(C—(CH₂)₂), 80.5 (C—OH), 123.1, 127.5, 127.7, 127.8, 143.1 (C-phenyl,CN)

[0182] IR (KBr, cm⁻¹): 3454 (s, broad), 3056 (w), 2966 (w), 2939 (w),2921 (m), 2229 (m, CN), 1659 (w), 1600 (w), 1495 (m), 1445 (vs), 1355(m), 1341 (m), 1279 (w), 1189 (m), 1165 (s), 1052 (vs), 870 (m), 749(s), 702 (vs), 637 (m)

[0183] Ligand II.4

[0184] Yield: 60%, empirical formula: C₂₅H₃₃NO, color: white; m.p.:66-67° C. (ethanol)

[0185] 1H NMR (CDCl₃): 0.93 (3H, t, CH₃), 1.28-1.45 (17H, m, CH₂),1.70-1.79 (2H, m), 3.02 (1H, s, C—OH), 7.26-7.58 (10H, m, phenyl)

[0186] 13C NMR (CDCl₃): 14.1 (CH₃), 22.6, 27.3, 27.6, 29.0, 29.2, 29.3,29.4, 29.5, 31.8 (CH₂), 43.1 (CH), 78.6 (C—OH), 120.6, 125.7, 125.8,127.5, 127.9, 128.4, 128.5, 143.0, 144.3 (C-phenyl, CN)

[0187] IR (KBr, cm⁻¹): 3355 (s, broad, OH), 3062 (w), 2952 (w), 2921(m), 2871 (w), 2852 (m), 2263 (m, CN), 1495 (m), 1470 (m), 1449 (s),1262 (m), 1177 (m), 1057 (s), 893 (m), 753 (s), 747 (s), 697 (vs)

[0188] MS: (LH⁺−H₂O)=346.3 m/z, L=ligand

[0189] Ligand II.5

[0190] Yield: 72%, empirical formula: C₁₉H₂₁NO₃, color: white; m.p.:104.5° C. (ethanol)

[0191] 1H NMR (CDCl₃): 1.46 (6H, s, 2×CH₃), 2.88 (1H, s, OH), 3.90 (6H,s, 2×CH₃—O—), 6.86 (4H, d, phenyl (ligand)), 7.53 (4H, d, phenyl). TABLE1 Overview of the ligands of the formula II Complex R¹ R² R³ R⁴ R⁵ NuII.1 H H Ph Ph — O II.2 Me Me Ph Ph — O II.3 —(CH₂)5— Ph Ph — O II.4 MeMe H n-C₁₀H₂₁ — O II.5 Me Me p-An p-An — O II.6 Me Me Ph Ph — O

[0192] 2. Synthesis of the Complexes

[0193] The ligand II.1 (517 mg, 2.32 mmol) was placed in a baked-outSchlenk tube which had been flushed with argon, dissolved in 20 ml ofTHF (absolute) and deprotonated at −80° C. on a cold bath (EtOH, N₂) bymeans of n-BuLi (1.2 ml, 2.4 mmol, 2.0 M in pentane). After removing thecold bath, the solution was stirred at room temperature for 1 hour(color change: yellow to light red).

[0194] After addition of the transition metal halide (ZrCl₄, 0.27 g,1.12 mmol, 0.5 equivalent) at −80° C., the solution was allowed to warmand became dark red over a period of 1 hour. It was stirred for 18hours.

[0195] The THF was subsequently distilled off in a high vacuum, and theorange or brown residue was suspended in toluene.

[0196] The LiCl formed in the reaction was removed from the suspensionby filtration. The solution was subsequently evaporated to dryness in ahigh vacuum, and the residue was digested and washed 3× with 10 ml ofhexane (absolute). The solvent was siphoned off and the pulverulent,orange complex I.b.1 was dried in a high vacuum.

[0197] Yield: 75%, empirical formula: C₃₀H₂₄Cl₂N₂O₂Zr, color: brick red

[0198] 1H NMR (CD₂Cl₂): 1.29 (4H, s, 2×CH₂), 7.09-7.49 (20H, m,aromatic)

[0199] Complex I.a.1

[0200] As a deviation from the general method, the residue after the THFhad been distilled off was washed with CH₂Cl₂ and with hexane.

[0201] Yield: 61%, empirical formula: C₁₅H₁₂Cl₃NOZr, color: dirty orange

[0202] 1H NMR (CD₂Cl₂): 1.87 (8H, s, 4×CH₂, 2 coordinated THF), 3.81(8H, s, 4×CH₂—O, 2 coordinated THF), 4.54, 7.08-7.48 (10H, m, aromatic)

[0203] Complex I.a.2

[0204] Yield: 69%, empirical formula: C₃H₄Cl₃NOZr, color: yellowishbeige

[0205] 1H NMR (CD₂Cl₂): 1.92 (2×CH₂, 1 coordinated THF, broad), 2.88(broad), 3.79 (4H, 2×CH₂—O, 1 coordinated THF, broad), 4.50 (broad).

[0206] Complex I.a.3

[0207] Yield: 70%, empirical formula: C₆H₈Cl₃N₃Zr, color: lemon yellowAs a deviation from the general procedure, the complex was purified asfollows: after the THF had been distilled off, the complex was suspendedin CH₂Cl₂ and introduced onto a short Celite® column. It wassubsequently eluted using 50 ml of acetonitrile.

[0208] Complex I.a.4

[0209] Yield: 81%, empirical formula: C₁₇H₁₆Cl₃NOZr, color: whitishyellow

[0210] 1H-NMR (CD₂Cl₂): 1.64, 1.70 (6H, 2×CH₃), 1.87 (8H, s, 4×CH₂, 2coordinated THF), 3.75 (4H, s, 4×CH₂—O, 2 coordinated THF), 7.28-7.72(10H, m, aromatic)

[0211] Complex I.a.5

[0212] Yield: 73%, empirical formula: C₂₀H₂₀Cl₃NOZr, color: whitishyellow

[0213] 1H-NMR (CD₂Cl₂): 0.86-1.88 (m, CH₂-ligand and CH₂ fromcoordinated THF molecules), 3.76, 4.45 (s, CH₂—O, coordinated THFmolecules), 7.09-7.73 (m, phenyl)

[0214] 13C NMR (CD₂Cl₂): 23.2, 23.5, 24.4, 24.9, 25.4, 25.8, 28.2, 48.6(C—(CH₂)₂), 68.8 (O—CH₂, THF), 75.8, 76.4, 76.8 (C—O, isomers), 127.1,127.2, 127.7, 127.9, 128.0, 128.2, 128.7, 129.3 (C-phenyl)

[0215] Complex I.a.6

[0216] Yield: 81%, empirical formula: C₂₅H₃₂Cl₃NOZr, color: dirty yellow

[0217] 1H-NMR (CD₂Cl₂): 0.84-0.88 (m, CH₃), 1.24 (s, CH₂), 1.84, 2.06(8H, s, broad, 4×CH₂, 2 coordinated THF molecules), 3.72, 4.44 (8H, s,broad, 4×—O—CH₂, 2 coordinated THF molecules), 7.12-7.84 (10H, m,phenyl)

[0218] 13C-NMR (CD₂Cl₂): 14.2 (CH₃), 23.0, 25.8, 27.9, 28.9, 29.5, 29.7,29.8, 29.9, 32.2 (CH₂), 43.2, 44.2 (CH, 2 isomers), 75.7, 76.3 (C—O, 2isomers), 126.4, 126.7, 126.9, 127.4, 127.5, 127.8, 128.2, 128.4, 128.5,128.6, 128.8, 129.3, 129.6 (C-phenyl, 2 isomers)

[0219] Complex I.a.7

[0220] Yield: 62%, empirical formula: C₁₉H₂₀Cl₃NO₃Zr, color:yellow-orange

[0221] 1H-NMR (CD₂Cl₂): 1.37 (3H, s, CH₃), 1.72 (3H, s, CH₃), 1.81 (s,2×CH₂, coordinated THF), 3.65 (s, 2×CH₂—O, coordinated THF), 3.76, 3.87(6H, 2×s, 2×CH₃—O), 6.81-7.83 (m, phenyl)

[0222] Complex I.b.2

[0223] As a deviation from the general method, the residue after the THFhad been distilled off was washed with CH₂Cl₂ and with hexane.

[0224] Yield: 53%, empirical formula: C₆H₈Cl₂N₂O₂Zr, color: light yellow

[0225] 1H-NMR (CD₂Cl₂): 1.81 (m, CH2, coordinated THF), 2.57 (t, CH₂),3.67 (m, CH₂—O, coordinated THF), 3.84 (m, CH₂—O)

[0226] Complex I.b.3

[0227] Yield: 76%, empirical formula: C₃₄H₃₂Cl₂N₂O₂Zr, color: white

[0228] 1H NMR (CD₂Cl₂): 1.27, 1.48 (12H, 4×CH₃), 1.79 (4H, s, 2×CH₂, 1coordinated THF), 3.72 (4H, s, 2×CH₂—O, 1 coordinated THF), 7.21-7.80(20H, m, aromatic) TABLE 2 Overview of the complexes of the formulae I aand I b Com- plex R¹ R² R³ R⁴ R⁵ M X Nu I.a.1 H H Ph Ph — Zr Cl O I.a.2H H H H — Zr Cl O I.a.3 H H H H —C₂H₄ Zr Cl N CN I.a.4 Me Me Ph Ph — ZrCl O I.a.5 —(CH₂)₅— Ph Ph — Zr Cl O I.a.6 H n-C₁₀ Ph Ph — Zr Cl N H₂₁I.a.7 Me Me p-An p-An — Zr Cl O I.b.1 H H Ph Ph — Zr Cl O I.b.2 H H H H— Zr Cl O I.b.3 Me Me Ph Ph — Zr Cl O

[0229] 3. Polymerization Experiments

[0230] 3.1. Polymerization at Atmospheric Pressure

[0231] In a Schlenk tube which had been made inert, a solution composedof 20 mg of the complex to be examined, 1 ml of 30% strength by weightMAO solution (in toluene) and 50 ml of toluene was prepared. Thisreaction mixture was, unless indicated otherwise, stirred under anethylene atmosphere for 90 minutes at room temperature. The precipitatedwhite solid was filtered off, the solid was washed with methanol anddried under reduced pressure. The polymer was obtained in the form of awhite powder.

[0232] 3.2. Polymerization in an Autoclave

[0233] 20 mg of the complex to be examined, 2 ml of 30% strength byweight MAO solution in toluene and 400 ml of toluene were placed in a 1l steel autoclave which had been made inert. At 70° C., the autoclavewas pressurized with ethylene to a pressure of 40 bar. This pressure waskept constant during the 90 minute duration of the experiment byintroduction of further ethylene. The reaction was stopped by ventingand the polymer was isolated by filtration, subsequent washing withmethanol and drying under reduced pressure.

[0234] 3.3. Copolymerization of Ethylene/Hexene

[0235] The procedure of 3.2 was repeated, but 20 ml of 1-hexene wereplaced in the autoclave at the beginning together with the otherreagents.

[0236] 3.4. Polymerization Using Hydrogen as Molar Mass Regulator

[0237] The procedure of 3.2. is repeated, but 4 l of hydrogen (at STP)are introduced into the autoclave at the beginning.

[0238] The results are summarized in Table 3. TABLE 3 Polymerizationresults Copolymerization of ethylene/hexene Influence PolymerizationHexene of hydrogen of ethylene at Polymerization content on theatmospheric of ethylene at of polymerization pressure 40 bar copolymerof ethylene Yield η value Yield η value Yield η value [% by Yield ηvalue Complex [g] [dl/g] [g] [dl/g] [g] [dl/g] weight] [g] [dl/g] I.a.11.4 28.5 48.0 45.5 27.5 34.9 <0.8 23.5 24.1 I.b.1 0.2 18.5 I.a.2  0.1*17.0 I.a.3  0.1* 17.0 I.a.4 2.4 12.2 45.7 28.0 21.5  9.9 <0.8 10.4 10.9I.a.5 3.4 I.b.2  0.1** 11.8 I.b.3 1.0 14.6 20.0  9.8  9.7 12.2 <0.8 11.4 9.6

We claim:
 1. A complex of the formula I a or I b,

where the variables are defined as follows: M is selected from among Ti,Zr, Hf, V, Nb and Ta; y corresponds to the oxidation state of M minus 1;z corresponds to the oxidation state of M minus 2; Nu is selected fromamong O, S and N—R⁵; X are identical or different and are selected fromamong halogen, C₁-C₈-alkyl, C₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl andC₆-C₁₄-aryl, R¹ to R⁵ are identical or different and are selected fromamong hydrogen, C₁-C₁₈-alkyl, substituted or unsubstituted,C₂-C₁₈-alkenyl, substituted or unsubstituted, having from one to 4isolated or conjugated double bonds; C₃-C₁₂-cycloalkyl, substituted orunsubstituted, C₇-C₁₃-aralkyl, C₆-C₁₄-aryl, unsubstituted or substitutedby one or more identical or different substituents selected from amongC₁-C₁₈-alkyl, substituted or unsubstituted, C₂-C₁₈-alkenyl, substitutedor unsubstituted, C₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl, C₆-C₁₄-aryl,halogen, C₁-C₆-alkoxy, substituted or unsubstituted, C₆-C₁₄-aryloxy,SiR⁶R⁷R⁸ and O—SiR⁶R⁷R⁸; five- and six-membered nitrogen-containingheteroaryl radicals, unsubstituted or substituted by one or moreidentical or different substituents selected from among C₁-C₁₈-alkyl,substituted or unsubstituted, C₂-C₁₈-alkenyl, substituted orunsubstituted, C₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl, C₆-C₁₄-aryl, halogen,C₁-C₆-alkoxy, C₆-C₁₄-aryloxy, SiR⁶R⁷R⁸ and O—SiR⁶R⁷R⁸; where adjacentradicals R¹ to R⁴ may be joined to one another to form a 5- to12-membered ring which may in turn bear substituents selected from amongC₁-C₈-alkyl, substituted or unsubstituted, C₂-C₈-alkenyl, substituted orunsubstituted and having from one to 4 isolated or conjugated doublebonds, C₃-C₁₂-cycloalkyl, substituted or unsubstituted, C₇-C₁₃-aralkyland C₆-C₁₄-aryl; R⁶ to R⁸ are identical or different and are selectedfrom among hydrogen, C₁-C₈-alkyl, C₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl andC₆-C₁₄-aryl.
 2. A complex as claimed in claim 1, wherein Nu is oxygen, Mis selected from among Ti and Zr, X is halogen and at least one radicalR¹ to R⁴ is different from hydrogen.
 3. A process for the polymerizationor copolymerization of olefins using one or more complexes of theformula I a or I b as claimed in claim 1 or
 2. 4. A process forpreparing a complex as claimed in claim 1 or 2, which comprises firstlydeprotonating a ligand of the formula II

by means of a base and subsequently reacting the product with a metalcompound MXY+J, where M is selected from among Ti, Zr, Hf or V, and X ishalogen, C₁-C₈-alkyl, C₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl or C₆-C₁₄-aryl,where MX_(y+1) may optionally be stabilized by additional unchargedligands.
 5. A process for preparing a supported catalyst for thepolymerization or copolymerization of olefins, which comprisesdepositing one or more complexes as claimed in claim 1 or 2 andoptionally an activator on a solid support.
 6. A supported catalyst forthe polymerization or copolymerization of olefins which is obtainable bya process as claimed in claim
 5. 7. A process for the polymerization orcopolymerization of olefins using a supported catalyst as claimed inclaim 6.